exe files not opening

hi guys
i am running win 7 ultimate, recently i am facing problem with exe files to open, firefox , utorrent and other exe programs not opening. when click nothing happens. at startup utorrent runs, but when click it on taskbar it disappears.

following programs are not opening
FIrefox (need urgent fix)
utorrent
DAEMON Tools ISO
Foxit pdf reader (sometimes opens)

other programs runs normally, like IE 8, chrome,.

Please guide a quick fix for this, other than reinstall OS

System Specs
Win 7 Ultimate 64 bit
Core i5 2.3 Ghz
4Gb ddr3
640gb drive

Thanks
Asim

I've used this .reg file in the past when malware changed the .exe registry key.

Save it to notepad and save as a .reg file

Code:

Windows Registry Editor Version 5.00
[-HKEY_CURRENT_USER\Software\Classes\.exe\shell\open\command]
[-HKEY_CURRENT_USER\Software\Classes\secfile\shell\open\command]
[-HKEY_CLASSES_ROOT\.exe\shell\open\command]
[HKEY_CLASSES_ROOT\.exe]
@="exefile"
"Content Type"="application/x-msdownload"
[-HKEY_CLASSES_ROOT\secfile]

Or you can use this microsoft article with a different Content Type

http://support.microsoft.com/kb/950505

Code:

Windows Registry Editor Version 5.00[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.exe][HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.exe][HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.exe\OpenWithList][HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.exe\OpenWithProgids]"exefile"=hex(0):

Thanx Brady, that trick works. all programs back to normal

Thanx again.

now i need to enable firewall to my system.

I highly recommend cleaning your system. If the malware changed your executable before, it will again, if you don't clean out the system.